password

password, in computing, a sequence of characters used to authenticate a user’s identity and authorize access to a computer system, website, mobile phone, or other digital device. A password is intended to be secret (known only by an authorized user) and is often paired with a username to confirm an individual’s identity. Passwords can vary in length and may include numbers, uppercase and lowercase letters, and special characters; if a sequence includes only numbers, it is sometimes referred to as a passcode or a personal identification number (PIN). Computer passwords derive from the practice of using spoken or written words or phrases to safeguard groups and locations.

Computer passwords are a common feature of daily life, and they are sometimes so complex that even recording all of them may be prohibitively burdensome for individuals. Consequently, there is a debate in the cybersecurity industry about whether passwords remain effective security measures or should be replaced with other methods of verification, such as biometric analysis (authentication methods that use human characteristics, such as fingerprint scanning and facial recognition). Ideally, a strong password should be easy to remember and difficult for someone else to guess. Individuals should avoid using personal details, such as the names of children and pets, birthplaces, or other information that could be easily accessed from social media sites. To reduce the number of passwords that a user needs to remember, cybersecurity organizations recommend using a password manager—a program that stores and deploys all of a user’s passwords (on entry of the user’s password for the manager program).

Early uses of passwords

Passwords have been used throughout history to prove people’s identities. According to the Hebrew Bible, the spoken password “shibboleth” was used in the 11th century BCE by soldiers of Gilead; their Ephraimite enemies pronounced the word differently, making it an effective means of differentiating friends from foes. In the Roman Empire, soldiers were assigned “watchwords” that had to be spoken to the night watchmen. Also, during the Prohibition Era in the United States, admission to illegal speakeasies called for a special codeword or phrase.

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Development of computer passwords

There is a consensus among computer historians that the first computer passwords were employed by American computer scientist Fernando Corbató in 1961 to secure the Compatible Time-Sharing System (CTSS), a general-purpose operating system that allowed multiple users to share access. Because each CTSS user needed private access to the system, it became necessary to devise a method to differentiate between users. The easiest solution was to give each user a unique password that the CTSS could compare against a master password file.

In 1974 American computer scientist Robert Morris, Sr., invented “hashing,” a process by which a string of characters is converted into a numerical code. Consequently, a computer’s passwords no longer needed to be stored in a database on that computer, and the unreadable (“hashed”) versions of the passwords could be stored instead. In 1977 the U.S. National Bureau of Standards published the Data Encryption Standard (DES), a cryptographic algorithm (a mathematical function used to encrypt plain text) that greatly improved the security of computer passwords via its 56-bit code key. In 1979 Morris and American computer scientist Ken Thompson strengthened computer passwords by devising the concept of “salting,” whereby a hashed password included random additional data to confuse would-be hackers.

The DES was replaced in 2005 by the Advanced Encryption Standard (AES). Unlike the code key for the DES, the AES algorithm included the ability to increase its code-key length as necessary. This allowed passwords with AES encryption to be impervious to cryptanalysis and kept them from being cracked since the passwords could be extended beyond hackers’ processing power (see also cybercrime: Hacking).

Multifactor authentication and two-factor authentication gained widespread use in the late 2000s and early 2010s due to a rise in cybercrime and identity theft. At the time they began to be used, they represented the latest advancements in computer password protection. Two-factor authentication, which was patented by the American telecommunications company AT&T in 1995, requires a user to enter two types of identity evidence during the authentication process. Multifactor authentication provides an additional level of security by requiring a user to enter at least two, if not more, verification factors during the authentication process—such as an answer to a security question, a one-time code sent to the user’s e-mail address or smartphone, or a biometric factor such as a fingerprint or facial scan—which makes it more difficult for cybercriminals to access a user’s data.

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